This invention relates generally to an image alignment system and a method for producing and maintaining a visually seamless image between two or more side-by-side images that are projected onto a single screen.
The concept of projecting multiple side-by-side images onto a screen to produce a single visual image is well known in the art. One of the difficulties with projecting multiple side-by-side images onto a screen is to align the multiple side-by-side images so that they appear to the viewer as a single visually seamless image. In rear projection systems, which are often used on mobile equipment or in environments where shock or vibration are common, the multiple side-by-side images can get out of alignment as a result of external forces thus resulting in multiple side-by-side images which do not appear as a single visually seamless image. In use of the present invention with digital imagers, an image formed of pixels is projected onto the screen with a portion of the projected pixels in the image remaining differentially distinguishable from the rest of the image as the image changes. The present invention provides a method and apparatus that uses conventional components to capture the location of a reference pattern of pixels within or adjacent the projected image and then uses the coordinates of the reference pattern of pixels in the side-by-side images to produce a single visually seamless image and to maintain the multiple side-by-side images as a single visually seamless image.
U.S Pat. No. 5,619,255 discloses the use of multiple cameras to display a series of three images in a side-by-side arrangement.
U.S. Pat. 5,902,030 discloses a system where a fresnel lens is used to align the images.
Briefly, the present invention includes dedication of a portion of the normally changing pixels in a projected image, which is formed of multiple pixels, to a pixel reference mark. Normally, two or more images are simultaneously projected in a side-by-side relationship on the screen. The pixel reference mark appears in each of the side-by-side images projected onto the screen. A camera, which has a field of view large enough to encompass the pixel reference mark in each of the side-by-side images on the screen, enables a computer to determine the coordinates of the each of the pixel reference marks and generate a deviation signal represented of the visual misalignment of the side-by-side images. A drive member controllable by the deviation signal from the computer repositions one of the digital side-by-side images with respect to the other to thereby produce a visually seamless image. The camera can continually monitor the pixel reference marks to continually generate a deviation signal so that the side-by-side images can automatically be brought into alignment to produce a single visually seamless image.